The magnetic disk used for magnetic disk drive has been shifting from conventional horizontal (in-plane) magnetic recording system to perpendicular magnetic recording system for higher capacity.
At the same time, servo data recording is performed by using a device called as a servo track writer (STW). According to the recent high recording density, time required for recording servo data increases more and more, and hence the reduction of tact time is desired.
Then, instead of using the STW, using a magnetic transfer method has attracted interests, since it collectively records the servo data in a magnetic disk by using a master recording medium in which servo information is previously patterned.
The magnetic transfer system with respect to a perpendicular magnetic recording medium includes a perpendicular magnetic recording system which perpendicularly apply a magnetic field to a medium surface, and a horizontal magnetic recording system which horizontally apply a magnetic field to the medium surface. In general, the horizontal magnetic recording system has a preferable transfer characteristic with respect to a pattern miniaturization accompanied by high recording density compared with the perpendicular magnetic recording system.
At the same time, with high recording density of a magnetic disk drive, the requirement for track positioning accuracy of the head become severe year and year. As a technique for improving the track positioning accuracy of the head, a method including additionally recording positioning correction data in a servo area in which data is preliminarily recorded is given.
The waveform of reproduced data recorded by perpendicular magnetic recording system is rectangle same as the reproduced waveform of data recoded by magnetic head. Therefore, a compatibility of reproduced waveform between the data preliminarily recorded in the servo area by perpendicular magnetic recording system and the positioning correction data additionally recorded in the servo area by magnetic head is assured.
On the contrary, a reproduced waveform of data recorded by horizontal magnetic recording system is different from the reproduced waveform of data recorded by magnetic head. Horizontal magnetic recording system has an advantage over realizing higher recording density than perpendicular magnetic recording system. Therefore, the compatibility of reproduced waveform between the data preliminarily recorded in the servo area by horizontal magnetic recording system and the positioning correction data additionally recorded in the servo area by magnetic head is not assured.